Better late than never....
Finally got around to using the Masters leather kit I previously mentioned from DD. Nothing short of amazing stuff. Super easy to use, and the cleaner is extremely effective at pulling out the dirt. Took this pic just after I had just tried some of the "Strong cleaner" on half the seat bottom.....Essentially wiped it on with the foam applicator, and off with a MF towel. This was the result:
The stuff requires minimal agitation to pull dirt out (great for us lazy people), and doesn't leave any obtrusive smells. The ONLY complaint I have, is that in the case of the Range Rover (which, just about everything inside is leather) I cant see this kit lasting more than a year before refills are needed.